Add support for kiosk mode on the client. Make sure the settings are written in the lockbox.

Propagates the registration mode through the policy subsystem and lock it down in the lockbox.
Provides interface to query the values using the EnterpriseInstallAttributes class.

BUG=chromium-os:26246
TEST=unit_tests: *Enterprise*,*Policy*

Review URL: https://chromiumcodereview.appspot.com/9403010

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@123471 0039d316-1c4b-4281-b951-d872f2087c98
16 files changed